Tawny Frogmouth breeding success

An average brood size of two Tawny Frogmouth chicks

I have been monitoring the breeding success of Tawny Frogmouths Podargus strigoides in Canberra, Australia, for several years and have found that the pattern is fairly constant. About half the breeding pairs rear two young to fledging; a few rear three in any year and about a quarter rear one chick. The proportion of pairs which fail to rear any chicks is about 24% on average over the years, ranging from 17 – 34% (Figure 1). I do not disturb the birds to record clutch size, but it is known to range from 1-3.

Figure 1: The number of young reared per breeding pair of Tawny Frogmouths in 2006 - 2012.

In recent years I had thought that more birds were failing to rear young, but this is just the impression gained as I have added more pairs to the study in the past few years. Although I have been recording more failures, this has been in proportion with larger sample sizes, there is no statistical difference (χ² = 3.8, df = 6, P = 0.43). The main causes of failure, which are usually the loss of whole clutches or broods, are predation by unknown species, but likely Brush-tailed Possum or Brown Goshawk. One male was taken off the nest by a feral cat. A few nests have been blown out of their trees by strong winds.

Figure 2: The number of Tawny Frogmouth pairs which failed to rear any young in any year is proportional  c24%, to the number studied (r = 0.899, P = 0.003).

Further study will aim to determine whether there are any differences between the breeding success of frogmouths in grassy woodland, dry sclerophyll forest or suburban remnant woodland; or if there is any difference between years of drought and high rainfall. Fortunately the study has already covered these criteria.

A male Tawny Frogmouth protects his chick

Another cover shot

I received a copy of this book through the post a few days ago and it features another of my images on the front cover. The book has been written mostly by Adam Watson who has used his old notes on birds in his native north-east of Scotland from as far back as the 1940's for comparison with bird numbers in the same area today.

One of the largest differences has been the deep and widespread decline of the Capercailie, featured here on the cover: a magnificent bird, the largest grouse, one of those species which exudes character, and is indeed part of the character of the pinewoods.

The book is full of details on species, which give an insight to how different species have reacted to changes in the landscape, mostly man-made. Not all have declined, some have increased, and possible reasons are dicsussed in the book. Above all, these notes come from a time when there were very few ornithologists recording such data. There is no substitute for original notes made at the time

Cheese-plant   Monsteria deliciosa

The cheese-plant in the garden is flowering with several blooms. Hopefully they will develop into fruit and I can have a taste of the delicious custard apple /pineapple type flesh. The plant has thrived since we cast it out of the veranda when it became too big. Now it lives happily in its frost-free rain-forest under an evergreen canopy by the pond.

By-catch

The stick insect climbs onto Terry's hat

When mist-netting birds last weekend I came across this little beauty in one of the nets:

A Pink-winged Phasma Podacanthus typhon.

After I safely took her out of the net and we took a look at her, she instinctively climbed up whatever was near, in this case it was Terry. Then once she had explored around his hat and could not climb any farther, and had not found any green foliage to hide in, she opened her wings and flew off. And what marvelous wings she had - bright pink, wow!

It looked like she was a female as her abdomen was swollen, perhaps gravid. She can lay eggs without mating, by parthenogenesis, and if she does so, the offspring wold be all female. If she did mate the sexes would be mixed.

For further information on stick insects have a look at the following link:
http://www.ozanimals.com/Insect/Pink-winged-Phasma/Podacanthus/typhon.html

She opens her wings to fly off

She merged well with eucalypt leaves

Birds are returning after the drought

Adult female Turquoise Parrot

Last weekend was spent mist-netting birds out at the Weddin Mountains. John Rawsthorne organised the banding and we caught about three-hundred birds, an indication that birds are coming back in numbers a couple of breeding seasons after the drought. We caught several Turquoise parrots, in a mix of adult females and young birds of the year. So they have had a successful breeding season.

Chestnut-rumped Heathwren

We also caught four Chestnut-rumped Heathwrens, which I haven't seen in the area for several years. Two birds were adult and two were young of the year - the one illustrated is a young bird as it has buff tips to its coverts and its tail is all new in uniform length. Adults have no buff tips and they were moulting their tails, the outer feathers being shorter than the central ones.
 

Yellow-tufted Honeyeater

Most of the birds caught were honeyeaters; about a hundred each of White-eared and Yellow-faced, a few Yellow-tufted, Brown-headed and White-plumed, and single Fuscous, Black and Black-chinned. The Black Honeyeater is a bird of the farther west, drier country which had bred in the area earlier in the season but had now moved on. The Yellow-tufted and Black-chinned were evidence that the species were now breeding in the area after being absent for several years. Their food plants have probably been flowering well in surrounding places which have held numbers in refuge during the drought.

Yellow-faced Honeyeater

The flocks of Yellow-faced and White-eared Honeyeaters were largely composed of young birds. Some of these were in early stages of their first post-juvenile plumage moult and others were further on, signifying that there were probably two cohorts of young birds; one from nests initiated early in the breeding season and the other of birds from second broods. So there has been a very successful breeding season in the area in 2012.

Black-chinned Honeyeater

The netting site at the Weddin Mountains is a long-term study site, so it will interesting to see what birds are recruited into the breeding population in 2013.

Happy New year.

10,000 UP

Yeh, the 10,000th visitor has just read this blog. Thank you everyone of you who has checked in for a look. That makes it all worthwhile. It is good to share experiences and news, and it's good fun.

Meanwhile, the other day while sitting on the veranda  I was thinking that I hadn't seen any sparrowhawks, or evidence of their kills, in the garden yet this post-breeding season. And what happened yesterday while I was out talking to the chickens, a beautiful hen Collared Sparrowhawk came swinging in through the shrubbery, over the chickens' heads and grabbed a House Sparrow. She then flipped over and into the neighbours' garden where she mantled her prey.

She stood there for a few minutes with the sparrow in her grasp, ensuring that it was definitely dead before she began to pluck it. Never releasing her grip all that time, she clearly held it tight in a constricting hold, so that it died of suffocation.

She was a stunning full adult, with a slate-blue back and head, rich red collar and belly stripes. The females usually take larger prey  such as Starlings or Common Mynas, and the smaller males take the sparrows and wrens. But, now she knows the sparrows are around the chicken house, where there are always food scraps, she will be back. And others will pass through too I'm sure.

Silk Tree

The weather is hotting up for summer now, so I am spending more time around the house. And when coming home yesterday I noticed that our Silk Tree Albizia is now not only escaping out of the back yard but seems to want to come into the front door.

Having spread its branches through the fence, it is now reaching over to the doorstep, but we like it, so it is welcome. These trees grow to fifteen metres or so in height up in Queensland, where there are native species. But here in Canberra they are not native and pretty rare. Our one came with the house when we moved in and it is a bit bonsai-ed as it is growing in  a walled section on the patio.

Backyard Chickens

We keep a small flock of chickens in the back yard, partly for eggs and partly as pets. However, I also use them for foraging behaviour experiments, and as they are all individual, this makes it easy to make good observations. here is a selection of portraits of the current flock members, they are all bantams.

Hiver, a white Silkie

Teal, a Pekin

Hermione, another Pekin

Thompson, with a P, her twin Thomson, without a P, looks identical but isn't.
They are Plymouth Rocks - very swift afoot

Nancy, a new young Wyandotte

Chalk and Cheese, the two new young Light Sussex twins

Islay, a young buff Silkie

Islay,  close up of her face

A good bath

There is nothing like a good bath for a girl to feel and look good

Hiver in her dust bath, looking a bit grubby

Really getting into it, dirt flying all over the place

Hiver all dry and fluffy after her bath

Doesn't she look good now!

More book reviews

There have recently been a couple more reviews of my book Eagle Days including one in the Scotland on Sunday photographed below.

And another in the BBC Wildllife Magazine saying,

  'captures the experience of following a truly wild bird wonderfully, and plenty of other wildlife is seen in the pursuit. This stimulating book will make readers want to head for the Highlands themselves.' Derek Niemann.

All the reviews have been favorable and I find it interesting to see the different topics and aspects which the reviewers have caught onto and chosen to highlight. I deliberately wrote the book with a weaving text, integrating the life of eagles as much as they are themselves integrated with the Scottish Highlands and all they encompass. We all see things differently. If only we all cared for eagles.

Cover shot

The recent edition of the Australian Field Ornithologist has used one of my images for the cover shot. The bird featured is a White-faced Robin Tegellasia leucops, and together with another shot in the main text it illustrates a species whose display behaviour is described in an article by John Rawsthorne and Richard Donaghey. 

Double Pink feeding her chick

Double Pink is a very well marked bird, and those markings
 blend in so well with the woodland background

The colour-banded Tawny Frogmouth, Double-Pink, which was rescued and successfully released back to the wild by the RSPCA, and her partner have lost one chick. It probably fell from the nest - they are terrible fidgets those young frogmouths - and then scavenged by a Red Fox, which is a common feral predator in the Canberra area.

However, the good news is that they still have one chick, it is fit, healthy and almost ready to fledge. Click on the link below to watch her at the nest with her chick.

Double-Pink feeding her chick

A close call

The colour-banded Tawny Frogmouth has two chicks, not one as first thought when they hatched. It is always difficult to see just how many there are when they are small and covered by an adult. But now they are more than two weeks old, beginning to fidget and are ever inquisitive - peering over the edge of the nest to what is going on down below and all around.

Which is just as well, for while I was watching them today, there was a chorus of alarm calls, mostly from Noisy Miners, screeching nearer and nearer. When I looked around at what the frogmouths were watching I saw a Brown Goshawk flit through the trees, around the frogmouths' nest tree, and then gone. It was hot today, about 33 degrees, so the frogmouths had been sitting quietly with their bills open to catch a breeze and cool down. Then as the alarms went off, they clipped their bills shut, half closed their eyes, and gently eased into their broken-branch pose. Once the danger was passed they gently relaxed and opened their bills again. The adult never heeded me much, but the chicks seemed to think I was fascinating, staring at me continuously.

A Quiet Vegetarian

Shingleback eating flowers

While out in the woods today I came across this little guy, a shingleback lizard. I see these animals most days I am out in the local woods, but usually I just say hello and walk on by, leaving them in peace. They are such quiet, passive animals, and almost completely vegetarian.

I could see this one from way off as I walked along a dirt road. It was struggling to pull down the long stems of a feral weed, a crucifer of some sort, to get at the flowers. But as it has such short legs and toes it could barely bend the stems over. So I pulled a few flower stalks and presented them to it. The shingleback took them straight away, no fear. I carried on chatting to it and gathered a heap of flower heads. Soon it was  eating out of my hand, it's lips touching my fingers as I held the stalks so it could pull off all the rich protein-filled parts of the flowers. 

A marvelous experience, to be trusted like that.